Video cameras are widely used in many client applications, such as webcam recording programs, video conference tools and Instant Messenger (IM) tools.
Referring to PRIOR ART FIG. 1, a system 100 includes a camera-use application block 102, a WINDOWS Driver Model (WDM) capture filter 104, and a physical video camera 110. The block 102 includes multiple camera-use applications, e.g., MSN MESSENGER 108A, YAHOO MESSENGER 108B, SKYPE 108C, and “360 Degree Web FACE” (FACE) application 114. Particularly, the FACE application 114 in the block 102 is an intelligent logging on and locking/unlock application developed by O2Micro Inc.
The WDM capture filter 104 is a standard MICROSOFT DIRECTX component which interacts with a device driver (not shown) of the camera 110. The device driver of the camera 110 may be formed as a driver file with an extension such as “.dll.” Once the WDM capture filter 104 links the device driver of the camera 110 to one application, the device driver of the camera 110 will not be available for other applications. In other words, the WDM capture filter 104 only allows one application to use the data captured by the camera 110 at any given time.
For example, once the FACE application 114 requests access to the video camera 110, then the WDM capture filter 104 is called and the device driver of the camera 110 is loaded. After configuration, the camera 110 starts to work and the FACE application 114 can operate normally for facial recognition. When another application, such as the MSN application 108A, attempts to use the camera 110 while the FACE application 114 is using the camera, the camera's device driver is not available to be accessed by the MSN application 108A. There will be a conflict in sharing the camera 110, and the later-calling application MSN application 108A will not be able to use the camera 110.